Bare in mind there is a LOT more to making horse power than throwing a bunch of specific parts together and hooking it to a dyno.

There is 20-30 hp difference in the honing jobs done on cylinder walls.
There is 10-20 hp difference in the rings that are used. full circle?
Piston crown detailing makes up to 30 hp difference on many engines.
We know that thin synthetic oil is good for 1 1/2 % more power, instantly.
Then you use a Jessel drive and get the cam timing perfect for what the combination wants,
change pushrods to find any harmonic unbalance and get the best numbers.
etc.

Lot of "minor" details done by skilled craftsmen add up to more hp than what can be duplicated by the hot rod masses.

You can bet your money that the AFR engines are detailed to the max in every way, shape, form, and fashion.

Realisticly IMO if most of us put together the identical parts list we would be doing good to get 90% of the stated figure.